I had my ECM replaced and still experienced the whine. Did a little further reading and did a little testing and realized it's the THROTTLE BODIES. Here is how you can tell if the noise is coming from your throttle bodies or ECM.
- Pop your hood.
- Put the car in Neutral.
- Set ignition to ON.
- Roll your windows down.
- At this point...it should be silent.
- Now put the car into gear. I usually go with 2nd. You should hear the whine start right away.
- Now put your ear near each throttle body and confirm. I could hear each throttle body whining.
I had my service manager convinced it was the ECM...and it turns out that wasn't the problem. Here is a video of the noise well. Car is in gear.
Throttle Body Whine